Anchoring method and apparatus



June 23, 1959 R. F. BAUER ETAL 2,891,770

ANCHORING METHOD AND APPARATUS Filed. Jan. 1:, 1955 4 Sheets-Sheet 1 12 INVENTORS. l 2 Roars-RTE BAUER HAL STRATTON I,I :1 49 .50 50 BY ATIDRAE YS.

June 23, 1959 Filed Jan. 1:5, 1955 R. F. BAUER ET AL ANCHORING METHOD AND APPARATUS 4 She ets-Sheet 2 55 73 72 as 25 5/ 1 j a 52 Q9 54 O O as INVENTORS. ROBERT E BAUER HAL STRATTON- ArTon /ysrs June 1959 R. F. BAUER ETAL ANCHORING METHOD AND APPARATUS IN V EN TORS. ROBERT F BAUER HAL S TRATTON 4 Sheets-Sheet 3 /66 I'll M a/kw M A TTORNEYS n 1959 R. F. BAUER ETAL ,89 ,770

ANCHORING METHOD AND APPARATUS Filed Jan. 1:5, 1955 Sheets-Sheet 4 /3/ /a0 72% FIG. 61

INVENTORS. ROBERT I. BAUER HAL STRATTON ATTORNEYS 2,891,770 Patented June 23, 1959 AN CHORING METHOD AND APPARATUS Robert F. Bauer, Whittier, and Hal Stratton, La Habra,

Califi, 'assignors to Shell Oil Company and Continental Oil Company, both corporations of Delaware, and The Superior Oil Company and Union Oil Company of California, both corporations of California, all of Los Angeles, Calif.

Application January 13, 1955, Serial No. 481,529

11 Claims. (Cl. 25-13) This invention relates to an improved method and apparatus for anchoring members in earth formations.

Although the invention may be used to anchor members in terrestrial formations, it is ideally suited for anchoring members in underwater formations. In co-pending application, Serial No. 468,214, filed November 12, 1954, now Patent No. 2,808,229, there is described a method and apparatus for drilling underwater wells from a floating vessel. As a preliminary step in drilling in accordance with the invention of that co-pending application, various members must be anchored in the underwater formation both to maintain the floating vessel in its desired location and to secure guide means adjacent the well to guide equipment in and out of the well. This invention provides an improved method and apparatus for securely embedding in a formation anchoring members which can be used for both purposes.

In terms of method the invention comprises the steps of forming a hole in a formation and lowering the anchor conduit in the hole as the hole is formed. Preferably, an anchor line is attached to the member and the anchor line is supported above the formation as the member is lowered into the hole.

In one embodiment where relatively soft formations are encountered, the method includes the steps of jetting a fluid out the lower end of the member against the formation to form a hole and lowering the member into the hole as the hole is formed. The formation is then al' lowed to slough or settle around the member to anchor it firmly in position. Alternatively, the anchoring member may be cemented in place or provided with movable flukes which may be forced into the formation.

In another form of the invention, where relatively hard formations may be encountered, a bit is removably attached to the lower end of the member, which may be in the shape of a conduit, and the conduit which is part of an elongated tubing is rotated to cause the bit to cut the formation. After the conduit is lowered to the desired depth, the bit is then removed from the conduit, leaving the conduit buried in the formation.

In terms of apparatus, the invention contemplates anchoring apparatus comprising an anchor conduit and an anchor line attached to the anchor conduit. In a preferred form, one end of the anchor conduit is adapted to be attached to a source of fluid so the fluid may be discharged out the other end of the conduit, and flukes are pivotally mounted on the anchor conduit to increase its holding power in the formation in which the anchor conduit is embedded.

In another embodiment, the anchoring apparatus comprises an anchor conduit having an external projection and a sleeve disposed around the conduit and provided with an inwardly extending surface adapted to support the projection. The sleeve is adapted to rest on the surface of'the formation and thereby support the conduit. An internal dog or stop is attached to the sleeve to engage the projection on the conduit and limit the rotation of the conduit with respect to the sleeve when the projection is supported by the inwardly extending sleeve surface. Preferably, the dog is pivotally mounted so that rotation of the conduit is limited only in one direction. Upwardly extending anchor lines or guide lines are attached to the sleeve, and outwardly extending support arms are attached to the sleeve to provide support for it on the formation, this structure being an embodiment of a drilling base. For the purpose of describing this invention the terms anchor line and guide line are used synonymously.

These and other aspects of the invention will be more clearly understood from the following detailed description in which: 7

Fig. 1 is an elevation illustrating how a conduit having an anchor line attached thereto may be jetted into a formation from a floating vessel;

Fig. 2 is an enlarged view of the anchoring apparatus of Fig. 1;

Fig. 3 is an elevational 'view of the anchor conduit in its final position after the formation has been allowed to settle around it;

Fig. 4 is an elevation showing the anchoring in a formation of a well conduit to which there are attached a pair of guide lines;

Fig, 5 is a sectional elevation of the well conduit of Fig. 4 after it has been located and cemented in its final position in the formation;

Fig. 6 is an alternate embodiment showing how a well conduit with guide lines may be anchored in a formation using a retrievable drill bit in the lower end of the well conduit;

Fig. 7 is a sectional elevation of the well conduit and drill bit of Fig. 6;

Fig. 8 is a view taken on line 8-8 of Fig. 7; and

Fig. 9 is a view taken on line 9-9 of Fig. 7.

Referring to Figs. 1 through 3, an anchor conduit 12 which is to be anchored into a formation 13 underlying a body of water 14 has its upper end releasably sealed in the lower end of an elongated, cylindrical, jetting tool 15 which is provided with a first relatively large longitudinal bore 16 of greater diameter than the outside diameter of the anchor conduit. The first bore of the jetting tool is stepped down to a second bore 18 which fits snugly around the outside diameter of the anchor conduit. The second bore is stepped down to a third bore 20 which ends near the upper end of the jetting tool. A shoulder 21 formed between the second and third bores rests on the upper end of the anchor conduit. A shoulder 22 formed between the first and second bores supports a conventional packing material 23 disposed in the annular space between the anchor conduit and the first bore of the jetting tool. The outer portion of the first bore is internally threaded to receive an externally threaded retaining ring 25 having an internal diameter to fit snugly around the outside diameter of the anchor conduit. A shear pin 26 is threaded through the retaining ring and extends into the anchor conduit to hold the conduit within the jetting tool.

A fluid inlet 28 in the side of the jetting tool at its upper end joins the third bore and is internally threaded to receive a nipple 29 attached to the lower end of a hose 30 having its upper end attached to the discharge of a pump 32 carried by a floating vessel or ship 34. A half-ring 36 welded to the top of the jetting tool carries the lower end of a supporting cable or line 37 extending up through a cellar 39 in the center of the ship and having its upper end attached to a hook 40 on a traveling block 41 which in turn is attached to the traveling end of a hoisting cable 42 supported in a conventional manner by crown block 43 on the upper end of a mast 44 mounted on the ship adjacentthe cellar. A draw-works 3 45 and power unit 46 are arranged to raise and lower the hoisting cable as required.

The lower end of an anchor line 48 is attached to a ring 49 secured to the upper portion of the anchor conduit and the upper end of the anchor line extends to the water surface where it is supported on the ship. A pair of diametrically opposed flukes 59 are pivotally attached at their lower ends to the anchor conduit adjacent its lower end, and each fluke is provided with a chain 51 having one end attached to the fluke and the other end attached to the anchor conduit to limit the outward travel of the fiukes.

The operation of the apparatus of Figs. l through 3 to anchor the conduit is as follows: With the anchor conduit assembled in the jetting tool as shown in Figs. l and 2, the hoisting cable is lowered until the lower end of l B anchor conduit is adjacent the formation. Fluid, for example water, is pumped clown the hose through the jetting tool and out the lower end of the anchor conduit. If desired, the lower end of the conduit may be pro vided with orifices or jets to increase the discharge velocity of the fluid and improve the cutting action of the fluid into the formation. As the fluid jcts or washes a hole into the formation, the hose, hoisting cable. and an chor line are lowered until the anchor conduit is in its desired position. General experience has indicated that in formations such as those encountered off the coast of California, a depth of between 25 and 40 feet is usually adequate to secure firm anchoring of the anchor conduit. The apparatus is then maintained in the hole until the formation settles around the tool. The hoisting cable is then raised causing the fiukes to be forced outwardly into the formation and then additional strain on the hoisting cable causes the shear pin to shear, releasing the jetting tool and leaving the anchor conduit in the position shown in Fig. 3. Thus the anchor is firmly embedded in the formation and will not drag as will conventional anchors which are merely lowered to the ocean bottom. Furthermore, the anchor is inexpensive and readily expendable. As an alternative procedure in formations which do not readily tend to settle around the anchor conduit, cement may be pumped down around the conduit to bond it firmly to the formation.

Referring to Figs. 4 and 5, an anchor conduit or well conduit 54 which is to be anchored in a hole 55' in an underwater formation 56 to hold a pair of guide lines or anchor lines 57 adapted to guide equipment in and out of a well as described in co-pending application Serial No. 468,214 filed November l2, 1954 is provided at its upper end with an internal left-hand thread 53 (Fig. Conventional drill pipe is coupled to the upper end of the well conduit by a swedge 59 having an internal righthand thread at its upper end and an external left-hand thread at its lower end to make up an elongated tubing. The drill pipe extends upwardly through a cellar 6 provided in a ship 61 which supports a platform disposed over the cellar. The platform supports a rotary table which may be mounted on gimbals as described in US. Patent No. 2,606,003 to compensate for the wave action of the water. A conventional kelly joint 64 extends through a kelly bushing 65 in the rotary table and the lower end of the kelly joint is attached to the upper end of the drill pipe. The upper end of the kelly is attached to a swivel 66 carried by a hook 67 and a traveling block 65 supported by a hoisting cable 69 strung over a crown block 79 at the upper end of a mast 71 mounted on the ship adjacent the cellar. A conventional draw-works 72 and power unit 73 raises and lowers the hoisting cable as re quired. One end of a drilling fluid hose 75 is connected to the swivel and the other end of the hose is connected to the discharge of a pump 76 arranged to supply a drilling fluid or water through the swivel, the kelly, the drill pipe, and out the lower end of the well conduit.

An external ring 78 on the upper end of the well conduit is welded to the top of an internal ring 80 provided in a sleeve 81 of a drilling base disposed around the upper portion of the Well conduit. A pair of diametrically opposed and radially extending guide post arms 82 are attached to the upper end of the sleeve. A separate guide post 33 is attached to the outer end of each guide post arm and extends a substantial distance above the upper end of the well conduit. The lower end of one of the anchor lines 5 is attached to the upper end of one guide post and the lower end of the other anchor line is attached to the upper end of the other guide post. Each anchor line extends upwardly and is supported by a separate support pulley 85 carried by forward and aft bridles 86 respectively which are attached to the ship. A separate freely hanging weight 88 is attached to the free end of each of the anchor lines.

A pair of diametrically opposed and radially extending support arms 91 are attached to the intermediate portion of the sleeve directly below the guide post arms and extend a substantial distance outwardly to provide support for the sleeve. A pair of gussets 91 are welded to the sleeve and the support arms. A separate depending spike 92 is provided in the intermediate portion of each support arm to anchor the support arms into the surface of the formation. A pair of flukes 94 are pivotally attached at their lower ends to the lower portion of the well conduit, and a separate chain 95 is attached to each of the fiukes and the well conduit to limit the outward travel of the dukes.

The apparatus of Figs. 4 and 5 is anchored in the formation as follows: With the apparatus assembled as illustrated in Figs. 4 and 5, the hoisting cable is lowered until the lower end of the well conduit is adjacent the surface of the formation. The pump is then started to force fluid against the formation and form the hole. As the hole is formed, the hoisting cable is lowered to permit the well conduit to be lowered into the hole. After the hole is formed to the required depth, i.e., with the support arms of the drilling base resting on the formation surface, the well conduit is maintained in the hole until the formation settles around the conduit, or the conduit may be bonded in place as shown in Fig. 5 with cement 96. Any upward force on the well conduit drives the flukes out into the formation and causes the conduit to become more firmly anchored in the formation. The drill pipe at the upper section of the elongated tubing is released from the conduit by rotating the drill pipe with the rotary table in a right-hand direction, as viewed from above. Since all of the drill pipe sections connect with ri ht-hand threads, the swedge is unscrewed at the lefthand thread of the well conduit. The inertia of the well conduit, sleeve, guide post, and supporting arms is usually adequate to permit the left-hand thread to be unscrewed, however the spikes in the support arms insure sufficient backup for the well conduit to permit the left-hand thread to be disengaged. The drill pipe and swedge are then withdrawn and drilling may proceed as described in co-pending application Serial No. 468,214 filed November l2, 1954.

Referring to Figs. 6, 7, 8 and 9, a well conduit 1% made up of several sections 101 of easing attached to each other by right-hand threads 102 (see Fig. 7) is suspended from a ship 103 over an underwater formation 10 1 in which a hole 106 is to be formed and the well conduit anchored. The upper end of the well conduit extends up into a cellar 108 provided in the central portion of the ship. A platform 110 over the cellar supports a rotary table 112 which carries a kelly bushing 114. A conventional kelly joint 116 is disposed through the kelly bushing. The lower end of the kelly joint is attached to the upper end of the well conduit by a suitable adapter (not shown), and the upper end of the kelly is attached to a swivel 118 adapted to receive a drilling fluid or water through a hose 120 connected to the discharge of a pump 122. The rotary table is powered by a rotary power unit 124 and by a shaft 126. The swivel is supported by a hook 127 and a traveling block 128 carried at the free end of a hoisting cable 129 disposed over a crown block 130 mounted at the upper end of a mast 131 on the ship adjacent the cellar. The hoisting cable is raised and lowered by a conventional draw-works 132 and power unit 133.

The lower end of the well conduit is of increased diameter to accommodate an annular insert 135 rigidly attached to the inside of the well conduit and spaced from the lower end thereof. The inside diameter of the insert is slightly less than the inside diameter of the normal portion of the casing. A drill bit 137 is removably attached to the lower end of the well conduit by virtue of being threadably engaged in the lower end of a removable cylinder 139 disposed within the insert and provided with an outwardly extending tapered portion 140 at its upper end which rests on a matching tapered portion 142 provided at the upper end of the insert. The cylinder is open from top to bottom and is provided with a first longitudinal slot 144 in its wall beginning near its lower end and terminating slightly above the center of the cylinder. A second longitudinal slot 146 is provided in the cylinder wall diametrically opposed to the first slot and begins near the lower end of the cylinder and terminates slightly above the first slot. An upright locking plate 148 is pivotally attached at its lower end within the cylinder in the plane of the slots by means of a stationary pin 150 disposed through the cylinder walls and the plate. At its upper end one edge of the plate is provided with a projection 152 having an upper surface 154 with a radius of curvature equal to the distance from the surface to the stationary pin. The opposite edge of the plate is recessed at 155 and adapted to receive one end of a compression spring 156 having its other end secured to a pin 157 threaded in the cylinder wall adjacent recess 155. The compression spring urges the upper part of the plate out of the second slot in the cylinder and into locking engagement in a registering slot 160 provided in the insert, the upper surface of the insert being provided with a radius of curvature matching that of the projection on the plate. A movable plunger 162 is disposed within the cylinder and is provided with a mushroom-shaped knob 163 at its upper end. A slot that extends from the lower edge of the plunger to a point approximately two-thirds up the length of the plunger forms two prongs 164 on each side of the slot which fit down over the plate within the cylinder. A movable pin 166 is disposed through the prongs to pass through a triangular opening 168 provided in an intermediate portion of the plate so that if the plunger is moved upwardly with respect to the cylinder, the movable pin slides upwardly in the triangular slot and forces the plate to move inwardly (pivot clockwise as viewed in Fig. 7) and free the projection on the plate from the notch in the insert. An expendable packing ring 170 packs off the space between the lower end of the cylinder and the lower portion of the well conduit. The plunger is provided with a pair of longitudinal bores 171, one bore extending down each prong to permit the easy passage of drilling fluid through the plunger, cylinder, and drill bit. The drill bit and the lower end of the well conduit which is serrated to facilitate penetration of the formation provide a cutting means positioned at the lower end of the conduit. The lower edge of the well conduit may also be provided with cutting blades or a diamond cutting surface.

A sleeve 174 of the drilling base is disposed around the upper portion of the well conduit and is provided with an internal support ring 176 which is arranged to support a pair of diametrically opposed and radially extending projections 178 (see Figs. 7 and 8) provided on the portion of the well conduit which is adjacent the formation surface when the well conduit is located in its final position as shown in Fig. 7. Three external spacer bars 180 are spaced on the well conduit just below the projections at intervals to centralize the well conduit within the support ring. A pair of diametrically opposed and triangularly shaped dogs 182 are mounted on the ring adjacent the inner surface of the sleeve to pivot about vertical pins 183 and permit the projections on the well conduit to move past them when the well conduit is in the position shown in Fig. 7 and is rotated in a clockwise direction as viewed in Fig. 8 but to prevent movement of the projections when the well conduit is rotated in a counter-clockwise direction. Each dog is provided with a spring 184 to urge it in its outermost position.

A pair of diametrically opposed and radially extending support arms 186 are attached to the intermediate portion of the sleeve. A pair of guide post arms 188 are attached to the upper end of the sleeve and extend in the same direction as the support arms. The lower end of a separate guide post 190 is attached to the outer end of each guide post arm, and the lower end of a separate anchor or guide line 191 is attached to the upper end of each guidepost. Each anchor line extends up into the cellar where they are temporarily secured on diametrically opposed sides by any suitable means. One anchor line then extends out the bottom of the cellar, over a protective roller 192 forward along the keel of the ship and down over supporting pulley 193 carried by a forward bridle 194; the other anchor line extends down out of the cellar around a protective roller 196, rearwardly along the keel of the ship, and over a supporting pulley 198 carried by a rear bridle 199 attached to a ship. Separate weights (not shown) are attached to the ends of the anchor lines as shown in Fig. 4.

The apparatus of Figs. 6, 7, 8 and 9 is operated as follows: The well conduit is made up of casing sections into sufiicient length to extend downwardly from the rotary table through the sleeve of the drilling base, which is supported below the cellar by the guide lines, and reach the top of the formation, the drill bit being disposed in the lower end of the conduit as illustrated in Fig. 7. The pump is started to circulate fluid out the lower end of the drill bit and the well conduit is rotated by means of the rotary table. The bit and lower end of the well conduit cut the hole into the formation and the fluid washes away the cuttings. After the hole is drilled for any suitable distance, the anchor lines are lowered to rest the sleeve and support arms on the formation surface as shown in Fig. 7. Drilling is then continued until the hole is drilled to the required depth minus the depth of the water. The section of the well conduit having the projections and spacer bars is then made up into the string of easing sections and drilling proceeds as described above. Additional sections of easing are added as required above the casing section having the projections and are temporarily spot welded together at their joints except for the joint directly above the projections, the resulting unit being an elongated tubing. When the well is drilled to the required depth, the projections on the well conduit rest on the support ring in the sleeve. Rotation of the casing in a clockwise direction (as viewed in Fig. 8) is unimpeded by the dogs. The well conduit may then be anchored in place by the use of cement as shown in Fig. 5 or the formation may be allowed to settle around the well conduit. The drill bit is then removed by a conventional Wire-line retrieving tool (not shown) which is lowered into the well conduit by means of a wire-line so that the retrieving tool latches onto the knob on the upper end of the plunger. Raising the wire-line pulls up the plunger and releases the plate from the notch in the insert so that the bit may be pulled up the interior of the well conduit.

The string of easing sections may be disengaged at the joint directly above the projections by reversing the di rection of rotation of the well conduit. Thus, when the casing is rotated in a counter-clockwise direction as viewed in Fig. 8, the dogs in the sleeves engage the projections on the well conduit and prevent rotation of the well conduit below the first joint above the projections. This allows the section of casing to become disengaged at this joint, the higher joints having been temporarily secured by spot welding to insure disengagement of the casing string at the proper point. The well conduit is now in position for drilling to proceed as described in copending application Serial No. 468,214 filed November 12, 1954.

Thus, the invention provides a simple and inexpensive method and apparatus for anchoring members in a formation so that the members can be used either to hold a floating vessel over a desired location or else anchor guide lines to facilitate guiding equipment in and out of a well.

We claim:

1. Apparatus for setting an anchor conduit in a forma tion underlying a body of water and for providing lat erally flexible elongated guide means extending from the anchor conduit to a vessel comprising in combination a floating vessel, an elongated tubing extending downwardly from said vessel and including an upper section and a lower section, the lower section being the anchor conduit and having cutting means at its lower end, means releasably connecting said upper section to the anchor conduit, operating means for lowering said tubing into contact with the formation and for rotating said tubing to cause cutting by said cutting means to advance the anchor conduit into the formation until the anchor conduit is substantially buried therein, a drilling base operatively connected to said operating means for lowering thereby, connecting means for connecting the drilling base to the upper end of said anchor conduit, laterally flexible elongated guide means connected to and extending between the drilling base and the vessel to provide means for guiding equipment in and out of anchor conduit.

2. Apparatus in accordance with claim 1, and wherein said cutting means includes a cutting surface at the l wer periphery of the anchor conduit.

3. Apparatus in accordance with claim 1, and wherein said cutting means includes a drill bit relcasably mounted in the lower end of the anchor conduit.

4. Apparatus in accordance with claim 3, and wherein said cutting means includes a cutting surface at the lower periphery of the anchor conduit.

5. Apparatus in accordance with claim 1 and including means on the vessel for pumping fluid down through the tubing while the tubing is being rotated.

6. Apparatus in accordance with claim 1 wherein said connecting means includes an external projection at the upper end of. the anchor conduit and an inwardly extending surface at said drilling base vertically aligned with the external projection on the conduit, said surface providing a seat for said projection to limit advancement of the anchor conduit into the formation.

7. Apparatus for setting an anchor conduit in a formation underlying a body of water comprising in combination a floating vessel, an elongated tubing extending downwardly from said vessel and including an upper section, a lower section. and a remotely operable releasable connecting means interconnecting the upper and lower sections, the lower section being an anchor conduit and having cutting means at its lower end, operating means supported on the vessel and connected to said tubing for lowering said tubing into contact with the formation and for rotating the tubing to cause cutting by said cutting means to advance the conduit into the formation until the anchor conduit is substantially buried therein, means connecting the upper end of the substantially buried anchor conduit to the top of the formation to prevent further advancement of the anchor conduit into the formation, said connecting means being operable from said vessel to release the connection between said upper section and the anchor conduit to enable separation and withdrawal of said upper section after the anchor conduit has been set in the formation.

8. The method of setting an anchor conduit in a formation underlying a body of water from a vessel and providing a drilling base at the formation having laterally flexible elongated guide means connected thereto and extending to the vessel to provide means for guidequipz' in and out of the anchor conduit which comprises making up an elongated tubing which includes the anchor conduit as a releasable lower section thereof, lowering said elongated tubing from the vessel as it is made up, forming a hole in the formation immediately under the anchor conduit and allowing the anutter conduit to advance downwardly into the hole as the hole is formed until the anchor conduit is substantially buried, lowering a drilling base having said guide means connected thereto and to the vessel downwardly to the formation adjacent the elongated tubing, connecting the drilling base to the upper end of the anchor conduit to enable guided movement of equipment in and out of the anchor conduit, and releasing and Withdrawing the upper section of the tubing from the anchor conduit.

9. The method of setting an anchor conduit having cutting means at its lower end in a formation underlying a body of. water from a vessel and providing a drilling base at the for 1&[1011 having laterally flexible elongated guide means connected thereto and extending to the vessel to provide means for guiding equipment in and out of the anchor conduit which comprises making up an elongated tubing which includes the anchor conduit as a releasable l we: section thereof, lowering said tubing from the vessel as it is made up, rotating the tubing to cut the formation with the cutting means and thereby advance the anchor conduit into the formation until the anchor conduit is substantially buried therein, lowering a drilling base having said guide means connected thereto and to the vessel downwardly to the formation adjacent the elongated tubing, connecting the drilling base to the upper end of the anchor conduit to enable guided movement of equipment in and out of the anchor conduit, and releasing and withdrawing the upper section of the tubing from the anchor conduit.

The method of setting an anchor conduit as defined in claim 8 and including pumping fluid downwardly through the elongated tubing while the hole is being formed to facilitate advancement of the anchor conduit into the formation.

11. The method of setting an anchor conduit as defined in claim 9 and including pumping fluid downwardly through the elongated tubing while the tubing is being rotated to facilitate advancement of the anchor conduit into the formation.

References Cited in the file of this patent UNlTED STATES PATENTS 

